Vehicle mirror assemblies can play a vital role in vehicle operation. Placement of the vehicle operator within the vehicle structure often makes direct line-of-sight to surrounding vehicle areas impractical. Yet such visual inspections of surrounding areas often are necessary for the vehicle operator to properly operate the vehicle. As vehicle size increases, so often does the difficulty of accurate visual inspections. Vehicles, such as school buses and commercial vans, typically have increased sizes and require visual inspection of areas in front and to the side of the vehicle. To this end, it is well known that vehicle mirrors may be front-end mounted to the vehicle to provide the widest possible field of view around the vehicle.
Early attempts at widening the operator's field of view focused on the use of convex mirrors. By increasing the size of the convex mirror, it was discovered that the field of view could be increased. Unfortunately, increasing the size of the convex mirror quickly becomes inefficient as the mirror itself begins to become an obstruction to forward viewing. To accommodate the need for increased field of view, without negatively impacting mirror size, it is known that a domed mirror lens may incorporate a varying radius of curvature from the center portion to one or more of the perimeter edges. The varying radius of curvature achieves a compacted wide field of view or viewing area within minimal space such that the driver can look forward of the vehicle with minimal blockage of vision. These mirrors with varying radius of curvature are commonly referred to as cross-over or cross-view mirrors.
Although the use of cross-over mirror designs has proven highly successful in the increase of viewing area while minimizing mirror size, present designs still can incorporate drawbacks. One of the drawbacks of these common cross-over mirror designs results from the reflection of the vehicle itself within the mirror. In many designs, the vehicle reflection is positioned within the center of the mirror and fills a significant amount of valuable viewing space. This results in a reduction of useful mirror surface area since the user does not commonly monitor reflection of the vehicle itself. Furthermore, images reflected in the mirror along the front and side of the vehicle often appear in the perimeter regions of the mirror. The reflections in the perimeter regions are commonly reduced in proportion due to decreasing surface radius of curvature in these regions of the mirror. This can result in distorted images with reduced image proportions such as long thin images. The reduction in image proportion can result in an increased strain on the driver to identify the objects reflected in these regions.
Another problem with many of the mirrors known today, including cross-over mirrors, is that they are designed or constructed with certain curvatures and structures to attempt to resolve certain concerns. This often results in significant distortion of the mirror tens surface and resulting image. It is believed that the mirror lens which create the best quality images are those which result from natural geometry and geometric figures, such as circles, ellipses, ovals, and the like.
It would, therefore, be highly desirable to have a mirror assembly that produces the highest quality reflective images, with the least distortion, and at the same time increase the useful surface area and keep the overall mirror size to a minimum. It would further be highly desirable to have a mirror assembly that improves image proportional reflection along the mirror perimeter to facilitate improved recognition.